Menthol cigarettes comprise a substantial portion of the American cigarette market with prevalence estimates reaching about 25%. A U.S. ban on menthol cigarettes would likely elicit changes in the behavior of menthol cigarette smokers and the tobacco industry. For smokers, these changes might include reduction or cessation of tobacco cigarette intake, substitution of menthol cigarettes with non-menthol cigarettes or other combustible tobacco products, or substitution with alternative tobacco products such as electronic cigarettes. For the tobacco industry, changes might include alternative brands aimed at menthol smokers to keep them smoking or the marketing of novel products targeting this population of smokers. The Province of Ontario implement on January 1st, 2017 one of the first bans on menthol products worldwide and preceded a full Canadian ban on October 1st , 2017. This legislation presents a unique and novel opportunity to understand the impacts of a menthol ban on smoking and industry behavior. The objective of this study is to conduct a long-term assessment of the menthol ban in Ontario to provide vital information about the potential impact of such an innovative ban. The specific aims of this study are to: 1) understand user behavior changes in tobacco use by pre-ban recent menthol smokers; 2) characterize industry and sales changes subsequent to a menthol ban; and 3) explore how menthol cigarette smokers transition from menthol cigarettes to either smoking cessation/reduction or replacement tobacco products. To address these aims, the research design includes a long term follow up of a cohort of smokers who were surveyed prior to the ban and examine smoking behaviors and attitudes two years after the ban. Behavioral data will be supplemented with an analysis of administrative sales data of tobacco products as reported to Health Canada, to examine changes in sales and changes in characteristics of products sold after the implementation of the bans in Ontario and nationally. Finally, we propose a concept mapping study to support the self-reported data and administrative data with an in-depth understanding of user behavior. This project will be the first rigorous long term evaluation of a real-world ban on menthol flavored tobacco in a large market. Results will reveal how menthol smokers respond to the ban and how the tobacco industry adapts over time, both critical issues for future regulation and associated public education messaging. This information is precisely the knowledge needed to guide the development and implementation of future regulation of menthol flavoring.